Abstract

Magnesium-doped boron nanoswords were synthesized via a thermoreduction method. The as-prepared nanoswords are single crystalline and β-rhombohedral (β-rh) phase. Electrical transportmeasurements show that variable range hoppingconductivity increases with temperature, and carrier mobility has a greater influence than carrier concentration. These results are consistent with the three dimensional Mott’s model (M. Cutler and N. F. Mott, Phys. Rev. 181, 1336 (1969)) besides a high density of localized states at the Fermi level compared with bulk β-rh boron.Conductivity of Mg-doped boron nanoswords is significantly lower than that of “pure” (free of magnesium)boron nanoswords. Electron energy loss spectroscopy studies confirm that the poorer conductivity arises from silicon against magnesiumdoping.

Received 19 January 2012Accepted 20 February 2012Published online 09 March 2012

Acknowledgments:

This project is financially supported by the National Natural Science Foundation of China (Grant Nos. 50872147 and U0734003), 863 Program (Grant No. 2007AA03Z305), and 973 Program (Grant No. 2007CB935503).